From: Sascha Hooker <s.hooker@st-andrews.ac.uk>
Reply-To: Marine Mammals Research and Conservation Discussion
<MARMAM@UVVM.UVIC.CA>
To: MARMAM@UVVM.UVIC.CA
Subject: Abstract - Bottlenose whale diet,
FA and SI analyses of biopsy samples.
New publication.
Hooker, S.K., S.J. Iverson, P. Ostrom, and S.C. Smith. 2001. Diet of
northern bottlenose whales inferred from fatty-acid and stable-isotope
analyses of biopsy samples. Canadian Journal of Zoology 79: 1442-1454.
Abstract: The Gully submarine canyon off eastern Canada has been
designated a pilot marine protected area largely because of the northern
bottlenose whales (Hyperoodon ampullatus) found there. Studies of this
species' diet elsewhere in the north Atlantic Ocean have suggested
specialization on the deep-sea squid Gonatus fabricii. We found a high
proportion of the congener Gonatus steenstrupi in the stomachs of two
bottlenose whales stranded in eastern Canada. In 1997, we collected remote
biopsy samples from free-ranging bottlenose whales off Nova Scotia: fatty
acids were determined from blubber samples and stable isotopes (carbon and
nitrogen) from skin samples. Although fatty-acid stratification throughout
the depth of the blubber layer was present (determined from blubber samples
of stranded animals), the magnitude of stratification was less pronounced
than in many other cetaceans, allowing some qualitative inferences to be
made from shallow biopsy samples. Fatty-acid patterns and stable-isotope
values from whales were compared with samples of G. fabricii from the
Norwegian Sea. Blubber fatty acid composition was similar in
characteristics to that of adult G. fabricii but was markedly distinct from
that of juvenile G. fabricii and other recorded prey species.
Nitrogen-isotope values implied that bottlenose whales (mean 15.3 ppt) and
adult G. fabricii (mean 13.7 ppt) occupy high trophic levels. Overall, the
results of these techniques concurred in suggesting that squid of the genus
Gonatus may form a major part of the diet of bottlenose whales in the Gully.
This paper is available on request as a PDF file from Sascha Hooker
(s.hooker@st-andrews.ac.uk).
Please note change of mailing address as follows:
Sascha K. Hooker, PhD
Sea Mammal Research Unit, University of St Andrews, St Andrews, Fife, KY16
8LB, UK
Phone: 44-1334-467201
Fax: 44-1334-462632
Email: s.hooker@st-andrews.ac.uk, shooker@is2.dal.ca
http://is.dal.ca/~whitelab/sh/sascha.htm
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